The lifetime of traditional light sources (incandescent, fluorescent, and high-intensity discharge lamps) is estimated through industry-standard lamp rating procedures. The number is typically determined by an operation that runs a large, statistically significant sample of a type of lamp until 50% have failed and that number of hours defines “rated life” for that lamp. Based on years of experience with traditional light sources, lighting experts can confidently use lamp life ratings, along with known lumen depreciation curves, to design the lighting for a space, and to determine equipment change schedules and economic payback. This aspect of predictive life or half-life of a light source is not true with Light Emitting Diodes (LED).
The primary reason why LED-based luminaires are immensely popular is because of their operational longevity and low power consumption. LEDs generally do not fail abruptly like traditional light sources; instead, their light output slowly diminishes over time. However, LED light sources can have such long lives that life testing and acquiring real application data on long-term reliability become problematic—new versions of products are available before current ones can be fully tested. On top of that, LED light output and useful life are highly dependent on electrical and thermal conditions that are determined by the luminaire and system design and environment.
Digital intelligent lighting control systems can switch and dim individual luminaries in a light scene or space (i.e., an “environment”), which provides a great amount of flexibility, for example, setting appropriate LED output under particular conditions including the level of LED lumen depreciation. For purposes of this disclosure, “environment” means generally and without limitation a space or area in which a luminaire or lighting system is installed. Such known lighting control systems have many user-friendly features for installation, programming, and operation. Lighting control systems can thus be integrated into a building management system as a subsystem of the central light controls.
A lighting control network includes one or more lighting devices; e.g., electrical ballasts (such as a luminaires), LED devices, and dimmers, among other things. In the case of dimmers, the dimmers must support specific interfaces for receiving control inputs and dimming the lights appropriately. Different lighting devices can support different control interfaces for dimming, e.g., to achieve a particular lumen level or light intensity as between different LED brands and/or powers.
The lumen level of a luminaire is the look and feel of the light produced by the luminaire. Current lighting control systems do not provide a system or method for allowing users to predict, after the fixture has been installed, when lumen degradation has occurred to the point where the light needs to be replaced. Current lighting control systems use, for example, environmental input sensors, which are directly connected to the luminaire to sense environmental conditions.
For example, current lighting control systems include a Digital Addressable Lighting Interface (DALI®) protocol-based system, which includes a controller, a driver, and a signal converter. The DALI® system is capable of regulating lumen level of a luminaire by adjusting a dimming level of the luminaire so long as the luminaire is the same make and type throughout the entire system, which has been pre-designed around such luminaires.
Thus, at least one drawback of the DALI® system and other current systems is that current systems may use a single or a fixed dimming control technology which may be set during lighting system commissioning and may not be adjusted during the life or state of degradation of a luminaire. Furthermore, these systems cannot control dynamic environments in which luminaires not present at the time of inception are introduced; that is, the lighting systems must be developed and tested with the technology and parameters available during initial commissioning of the lighting system. There is no system learning capacity to dynamically integrate new luminaires and different types of LEDs, for example, with different powers, into the system.
Thus, devices, systems, and methods for allowing a user who installs tens of thousands of luminaire systems to predict when and how much every luminaire has been degraded and/or adjust dimming level control over time provides enhanced convenience, control, and economics in lighting systems. The devices, systems, and methods may scale to very large numbers of luminaires at a global level. Such devices, systems, and methods may, for example, identify in real time the current state, such as ON/OFF, lumen level, and/or degradation state of at least one luminaire.
Such devices, systems, and methods may also be capable of maintaining the lumen levels of each luminaire regardless of dimming protocols, type of luminaire, or environmental characteristics associated with the luminaire.
Further, current techniques for luminaire dimming may be controlled by multiple standard protocols. The implementations are varied and the results cannot be correlated. The luminaires can control their light intensity or lumen level one at a time; e.g., every luminaire can have a sensor and a dimming control that can be set to a specific lumen level. Thus, when a group of luminaires occupy the same space, or same room, those luminaires will often be identical otherwise controlling the dimming level will not project a correct lumen level in the room. On the other hand, devices, systems, and methods which allow for any dimming protocol to be in the same space with a variety of luminaires/LEDs and yet generate a specific, overall lumen level for the space using the sensors and dimming control in real time provide further flexibility in lighting control systems.
For purposes of this disclosure, “protocol” means, for example and without limitation, one or more instructions, sequences, processes, algorithms, responses, or actions.
For purposes of this disclosure, “real time” means substantial concurrency. “Real time” is not used to imply any particular timeframe or limitation.